JP3476814B1 - Mold for semi-solid metal molding - Google Patents

Abstract

Abstract: PROBLEM TO BE SOLVED: To provide a mold for forming a semi-molten metal which has a simple structure and prevents a product defect due to a molten metal boundary of a semi-molten metal or residual gas. SOLUTION: A semi-molten metal forming mold for molding a product having a product shape in which a molten metal is formed when a semi-molten metal is injected and filled into a cavity portion, wherein a junction where the molten metal boundary is formed. By disposing the overflow portion at a position facing the outside from the outside via a communication passage, hot water and residual gas are discharged to the overflow portion to prevent product defects.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold for forming semi-molten metal, and particularly to a good molding by preventing a molten metal boundary generated when the semi-molten metal merges in an annular portion serving as a bearing in a cavity. The present invention relates to a semi-molten metal forming die for obtaining a product.

[0002]

2. Description of the Related Art A semi-molten metal forming method called a thixocasting method is a method of casting a molded product by filling a mold with a so-called light metal such as aluminum, magnesium or aluminum alloy in a semi-molten state. Is.

However, in the semi-molten metal forming method, the temperature of the molten metal at the time of forming is lower than that in the conventional casting method. It has the problem of being easy. This hot water level is particularly likely to occur when manufacturing a product having a complicated shape, for example, a product having a complicated shape having a portion where the semi-molten metal joins and is integrated in the mold, and when the hot water level occurs Since the strength of the molded product in that portion is significantly reduced, it is a big problem in carrying out the semi-molten metal forming method.

The mold used in the above-described conventional casting method has an overflow space portion near the confluence portion as a countermeasure against the molten water border generated at the confluence portion, and the molten metal border generated at the confluence portion is made into the overflow space portion. It is generally designed to be poured and removed from the molded product, and the mold used in the semi-molten metal forming method, like the mold used in the conventional casting method, is designed to remove the hot water generated at the joining part. In general, the structure is such that it is poured into the overflow space and removed from the molded product.

[0005]

However, when the conventional semi-molten metal forming die shown in FIGS. 10 to 12 is used, there are the following problems.

FIG. 10 is a schematic view of a cavity structure having a structure of an overflow space portion provided in a conventional mold for forming a semi-molten metal. The overflow space portion 108 shown in FIG. 10 is assumed to have a structure having, for example, an annular portion in a part of the cavity portion 100 corresponding to the shape of the molded product, and the overflow gate portion 103.
And the overflow portion 105, and the cavity portion 100 of the joining portion where the semi-molten metal M joins at the annular portion.
It is installed in one place.

As shown in FIG. 10, the size of the overflow gate portion 103 used in the conventional mold is shallow in the opening / closing direction of the mold and generally deep in the direction orthogonal to the opening / closing direction. Is designed.

This is for facilitating the working of the mold at the time of manufacturing the mold and for considering the release of the molded product at the time of molding. In the conventional casting method in which the metal is completely melted, the overflow gate portion 103 having the above-described structure allows the molten metal boundary Y to completely flow into the overflow portion 105 and be separated and removed from the molded product. There is nothing wrong with doing it.

FIG. 11 is a conceptual view of the behavior when the semi-molten metal M flows in the cavity 100 as seen from the mold closing direction. The behavior of the semi-molten metal M will be described with reference to FIG. . The semi-molten metal M that has flowed into the annular portion of the cavity portion 100 of the mold advances while gradually filling the annular portion as shown in FIG. 11A, and finally joins at the joining portion J. Since the temperature of the tip portion of the above-mentioned semi-molten metal M is reduced in the annular portion, even if the lowered tip portions of the semi-molten metal M merge with each other, they cannot be completely integrated, and as shown in FIG. The hot water boundary Y as shown occurs. In particular, in the case of high-speed injection, air or the like is entrained to form a large bath boundary Y.

In FIG. 11 (3), a part of the generated boundary Y is caused to flow out to the overflow gate 103 side together with the flow of the semi-molten metal M, which is different from the conventional casting method in which the metal is completely melted. Unlike FIG. 11 (4) and FIG. 11 (5), it is not possible to flow the entire molten metal boundary Y, whose fluidity has dropped significantly due to the further decrease in temperature from the semi-molten metal M, to the overflow section 105. As shown in (3), there is a problem that the molten metal boundary Y generated on the side opposite to the side on which the overflow gate portion 103 is arranged remains in the cavity 100, resulting in a product defect.

FIG. 12 is a conceptual view of the behavior when the semi-molten metal M flows in the cavity 100 as seen from the direction orthogonal to the mold closing direction. The semi-molten metal M of FIG. Explain the behavior. When the overflow gate portion 103 is formed in a conventional mold for semi-melting molding as shown in FIG. 12, unlike the conventional casting method in which the metal is completely melted, depending on the direction of the mating surface of the mold, a ring shape may be formed. Width of Cavity 100 Having a Portion and Overflow Gate 10
Due to the different width dimensions of 3, the cavity portion 100
There is a problem that a step is formed at the corner portion of the above, an air pocket is formed at the corner portion, and a gas defect or a molten metal boundary Y remains due to the air pool, resulting in a product defect. Such a problem is apt to occur particularly when the semi-molten metal M having poor fluidity is used.

The present invention has been made in view of the above problems, and an object thereof is to provide a mold for forming a semi-molten metal, which has a simple structure and prevents a product defect due to a molten metal boundary or residual gas. It is what

[0013]

In order to solve such a problem, in the first invention according to the present invention, an annular portion is provided.
When the semi-molten metal was injected and filled in the cavity portion which provides a semi-molten metal mold as cold shut occurs, communication passage position opposing sandwiching the merging section of occurrence of該湯boundary from the outside
And the semi-molten gold in the boundary of the molten metal flowing through the communication passage
Consisting of an overflow part for accepting a genus
One in which the overflow space is orthogonal to the opening / closing direction of the mold
Arranged over the entire width of the cavity viewed from the direction
It was

[0014]

In the second invention based on the first invention, the pair of communication passages are configured to have the same cross-sectional area. In the third invention mainly based on the first or second invention, the cavity portion is composed of a first cavity portion which is a main body portion and a second cavity portion which is additionally provided, and the first cavity portion. And a molten metal confluent part, in which the tip of the semi-molten metal filled in the second cavity part , which forms an annular part, flows from the left and right of the annular part and then joins and is integrated.
A first overflow portion and a second overflow portion are provided through two openings provided at positions facing each other with the melt confluence portion sandwiched from the outside, and the communication passages communicating with the respective openings. It was

In a fourth invention mainly based on the first or second invention, the cavity part includes a first cavity part forming a main body part, a second cavity part provided in association with the first cavity part, and a third cavity part.
It is composed of a cavity, and the melt merging portion where the distal end portion of the semi-molten metal is integrally joined after flowing from the left and right of the annular portion in the second cavity portion and a third cavity portion forming the annular portion, A first overflow portion and a second overflow portion are provided through two openings provided at positions facing each other with the melt confluence portion sandwiched from the outside, and the communication passages communicating with the respective openings. It was

According to a fifth aspect of the invention, which is mainly composed of the third and fourth aspects, at least one of the first overflow portion and the second overflow portion is provided at a position recessed from the mating surface of the mold. , The first which forms the communication passage
Overflow gate part and second overflow gate part
Axis passing through the is provided so as to intersect the vertical axis of the mold.
In the sixth aspect of the invention composed mainly of the fifth invention, a slide core pin disposed a slide core into and out of the mold, to prevent undercutting of said first overflow portion to the front end side of the slide core, were provided with pins punching cast to prevent undercutting of said second overflow section.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a mold for semi-molten metal forming according to an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic view of a mold for semi-molten metal forming in which a vertical axis of an overflow gate according to the present invention is arranged at a position coinciding with a vertical axis of a mold, and FIG. 2 is a half viewed from a mold closing direction of the mold. Explanatory drawing for explaining the behavior of the molten metal, FIG. 3 is an explanatory drawing for explaining the behavior of the semi-molten metal seen from the direction orthogonal to the mold closing direction of the mold, and FIG. 4 is the overflow space according to the present invention. FIG. 5 is an explanatory view for explaining the dimensional configuration of the portion, FIG. 5 is a sectional view of a main portion of a mold provided with an overflow space portion, and FIG. 6 is a position where the vertical axis of the overflow gate according to the present invention does not coincide with the vertical axis of the mold. FIG. 7 is a schematic view of a semi-molten metal forming die arranged in FIG. 7, FIG. 7 is an enlarged front view of an essential part of FIG. 6, FIG. 8 is an explanatory view in which an air vent is provided between the extrusion pin and the die, and FIG. 9 is A of FIG. −
FIG.

First, the difference between the first embodiment and the second embodiment will be described. In the first embodiment, the first overflow portion 5 and the second overflow portion 15 are provided on the mating surfaces of the molds, and the hot water boundary generated at the location where the semi-molten metal joins in the second cavity portion having the annular portion. First for removal purposes
The overflow gate section 3 and the second overflow gate section 13 are located on the same vertical axis, and at the same time, the vertical axis and the vertical axis of the mold are at least parallel to each other.

Further, in the second embodiment, the first overflow portion 55 and the second overflow portion 65 are provided at positions recessed from the mating surface of the mold, and the semi-molten metal is generated in the second cavity portion having the annular portion. The first overflow gate portion 53 and the second overflow gate portion 63 are positioned on a straight line for the purpose of removing the hot water boundary generated at the joining point, and the straight line and the mold vertical axis line are at least intersected with each other (mismatch). It is provided so that.

[0021]

[Embodiment 1] Hereinafter, Embodiment 1 will be described with reference to FIGS. 1 and 5 to describe the structure of a semi-molten metal forming die. Reference numeral 1 is a cavity part, 3 is a first overflow gate part, 5 is a first overflow part, 8 is a first overflow space part, 13 is a second overflow gate part, 15 is a second overflow part, and 18 is a second overflow space. Parts are shown respectively.

The cavity portion 1 includes a first cavity portion 1a forming a main body portion and a second cavity portion 1b connected to the first cavity portion 1a so as to be located above the first cavity portion 1a. They are arranged in a column.

The second cavity portion 1b is formed with an annular portion which serves as a bearing portion of the molded product. The semi-molten metal M is first filled in the first cavity portion 1a, and then in the annular portion of the second cavity portion 1b. Is a semi-molten metal forming die 10 that can flow from the lower portion to the upper portion while flowing in the left-right direction, and then can be merged and integrated in the upper portion.

Further, in the first embodiment, the first overflow space 8 and the first overflow space 8 are provided at opposite vertical positions separated from the annular portion of the second cavity portion 1b with the confluence portion J of the semi-molten metal M forming the molten metal boundary Y interposed therebetween. The second overflow space 18 is provided. The first overflow space portion 8 is located above the merging portion J, and the second overflow space portion 18 is located below the merging portion J.

Here, the first overflow space 8 is
It is composed of a first overflow gate section 3 and a first overflow section 5. Similarly, the second overflow space section 18 is composed of the second overflow gate section 13 and the second overflow section 15.

The second cavity portion 1b forming the annular portion and the first
The overflow section 5 and the second overflow section 15 are connected to the first overflow gate section 3 or the second overflow gate section 13, respectively. The first overflow gate portion 3 and the second cavity portion 1b
The first overflow part 5
The first opening 4 which forms an entrance leading to the
The second overflow portion 15 is provided at a portion where the overflow gate portion 13 contacts the annular portion of the second cavity portion 1b.
The second opening 16 is formed as an inlet leading to. In addition, the cross-sectional areas of the passages of the first overflow gate portion 3 and the second overflow gate portion 13 do not change on the way and the same cross-sectional area is maintained.

The first overflow space portion 8 and the second overflow space portion 18 of the present invention are the first overflow gate portion 3 and the first overflow portion 5, and the second overflow gate portion 13 and the second overflow gate portion 13 shown in FIG. The present invention is not limited to the configuration including the overflow portion 15, and may be, for example, the first overflow space portion 8 having a shape in which a portion called a first overflow portion 5 as shown in FIG. 1 is greatly extended. May be.

The semi-molten metal forming die 10 shown in FIG.
A fixed mold 20 and a movable mold 30 are provided, and both molds 20, 3
A cavity portion 1 corresponding to the shape of the molded product is formed inside 0.

At the lower ends of the fixed mold 20 and the movable mold 30, a tiltable injection device 34 for injection-filling the semi-molten metal M into the cavity 1 is provided. Between the injection device 34 and the cavity portion 1, a vertical sleeve 36 in which the semi-molten metal M is loaded from the holding container is brought into contact with the lower ends of the fixed die 20 and the movable die 30 to inject and fill the cavity portion 1. An inlet 32 is provided for this purpose.

Next, referring to FIG. 4, the dimensional configuration of the first overflow space 8 and the second overflow space 18 and the confluence J of the semi-molten metal M forming the second cavity 1b.
The dimensional configuration of will be described.

The first overflow portion 5 and the lower portion are disposed in the upper portion facing each other, which is separated from the annular portion of the second cavity portion 1b with the joining portion J of the semi-molten metal M forming the molten metal boundary Y interposed therebetween. The second overflow section 15 is provided.

The first overflow gate part 3 or the second overflow gate part 13, which forms a communication path between the second cavity part 1b and the first overflow part 5 and the second overflow part 15, is on the same straight line and at the bath boundary Y. Are arranged so as to be substantially orthogonal to the confluence J.
Therefore, it is possible to more efficiently introduce the molten metal boundary Y generated at the merging portion J into the first overflow portion 5 and the second overflow portion 15 and remove it so that the molded product or the molten metal boundary Y portion does not remain. It is possible.

The cross-sectional areas of the first opening 4 and the second opening 16 have a rectangular shape, and the width dimension is G (FIG. 4 (A)),
It is represented by the vertical width dimension H (FIG. 4B). On the other hand, the dimension thickness of the second cavity 1b of the confluence portion J in the upper part of the annular portion forming the second cavity portion 1b is represented by T.

In the first embodiment, the first opening 4 and the second opening 4 are provided in order to smoothly discharge the hot water boundary Y generated at the joining portion J.
The size of the cross-sectional area of the opening 16 is reduced so that the first overflow gate portion 3 or the second overflow gate portion 13 is formed.
It is designed to increase the flow velocity inside.

Therefore, the second cavity 1b of the confluence J
When the thickness dimension T of each of the first opening portion 4 and the second opening portion 16 is compared with each of the lateral width dimensions G1 and G2, in general, G (G1 =
G2) <T is preferably determined, and G
The ratio of (width dimension of the first opening 4 and the first opening 16) / T (thickness dimension of the second cavity 1b of the confluence J) is
It is preferably in the range of 30 to 70%.

As shown in FIG. 4B, the vertical width H1 of the first opening 4 and the vertical width H2 of the second opening 16 are also shown.
Have substantially the same vertical width dimension H (H1 = H2), and the relationship with the vertical width dimension W of the second cavity 1b is H /
It is preferable to determine W = 70 to 105%. In Example 1, G / T = 65%, H / W = 100%
The second cavity 1b having the following structure was used.

In the first embodiment, the first opening 4 and the second opening 16 are described in such a form that the vertical width and the horizontal width can be adjusted to optimum dimensions. The first overflow space portion 8 and the second overflow space portion 18 having a desired size may be arranged at predetermined positions in consideration of the shape of the molded product and the mold opening direction. However, the shape is not particularly limited.

Further, the first overflow space 8 and the second overflow space 18 in the first embodiment are the second overflow space 18 and the second overflow space 18.
Of course, it is not necessary to provide it in all the confluences J in the cavity 1b, and it is a site where defects occur due to the occurrence of the molten metal boundary Y, and the first overflow space 8 in terms of mold design.
It is sufficient that the second overflow space 18 is provided at least at one of the sites where there is no problem.

Next, a semi-molten metal forming method using the semi-melt forming die 10 according to the first embodiment will be described.

First, a method for producing the semi-molten metal M will be described. A molding temperature containing crystal nuclei, which contains a crystal nucleus promoting element in which an aluminum alloy melt poured from a ladle into a holding container (not shown) is maintained at a superheat degree of less than 100 ° C. with respect to a liquidus line. The above-mentioned solid-liquid coexisting molten aluminum alloy has a thermal conductivity of at least 1 kcal / m · hr.
-The temperature of the molten metal in the holding container is sprayed directly from the outside of the holding container by pouring the molten metal directly from the holding container (not shown) having a material of not less than ° C to the vertical sleeve 36 without using a jig. Is cooled so as to be uniform.

A liquid phase ratio suitable for molding is cooled to the molding temperature and held for 5 seconds to 60 minutes, and held by an induction device (heating coil) in the process of crystallizing fine primary crystals into the molten metal. The temperature of each part of the molten aluminum alloy in the container was adjusted so as to be within the target molding temperature range (600 ° C. in the present Example 1) that shows a predetermined liquid phase ratio by the time of molding at the latest. .

The amount of the refining agent added to obtain fine spherical crystals is 0.0 when Ti alone is added.
If it is less than 3%, the effect of refining is small, and if it exceeds 0.03%, a coarse Ti compound is generated and ductility is deteriorated.
Is 0.03 to 0.3%.

When Ti and B are added in combination, Ti is 0.005
If it is less than 0.1%, the effect is small, and if it exceeds 0.3%, a coarse Ti compound is generated and the ductility decreases, so Ti is set to 0.005 to 0.3%. B, together with Ti, promotes miniaturization, but if it is less than 0.001%, the miniaturization effect is small, and if it is added in excess of 0.01%, no further effect can be expected. Is 0.001-0.01%
And

When the molten metal reaches a target uniform temperature in the holding container, the completed semi-molten metal M is filled in the vertical sleeve 36 of the injection device 34. When the vertical sleeve 36 of the injection device 34 is filled with the semi-molten metal M, both molds 20 and 30 are already closed, and the cavity portion 1 is formed between the fixed mold 20 and the fixed mold 30. ing.

Then, when the injection switch is turned on, the plunger rod 38 of the injection device 34 advances and the cavity 1 is filled with the semi-molten metal M. As the plunger rod 38 advances, the semi-molten metal M fills the first cavity portion 1a while flowing, and the flowing semi-molten metal M reaches the inlet of the second cavity portion 1b before long.

The semi-molten metal M reaching the inlet of the second cavity portion 1b branches into two left and right parts according to the shape of the annular portion which serves as the bearing portion, and then gradually rotates the annular portion clockwise and counterclockwise. While filling in the direction and proceed (Fig. 2 (1)),
Merging is performed at the confluence J (FIG. 2 (2)).

The temperature of the semi-molten metal M flowing through the tip of the semi-molten metal M drops when flowing through the second cavity portion 1b, and even if the lowered tip parts of the semi-molten metal M merge with each other, they are not completely integrated. Therefore, as shown in FIG. 2 (2), in the joining portion J, a molten metal boundary Y is formed so as to extend in a direction orthogonal to the flow direction of the semi-molten metal M immediately before joining.

After the molten metal boundary Y is generated at the merging portion J, the semi-molten metal M continues to flow into the first overflow gate portion 3 and the second overflow gate portion 13 which are provided in opposite directions. Y is entrained by the semi-molten metal M flowing inside the first overflow gate section 3 and the second overflow gate section 13 (FIG. 2 (3)).

The semi-molten metal M, which has begun to flow inside the first overflow gate section 3 and the second overflow gate section 13 while splitting, splits and separates the molten metal boundary Y which causes a product defect. Part 5 and second
It flows into the overflow section 15 (FIG. 2 (4)).

The semi-molten metal M is supplied to the first overflow section 5
And the second overflow portion 15 flows into the first cavity portion 1a and the second
The filling of the cavity 1 composed of the cavity 1b is completed (FIG. 2 (5)). When the filling is completed, both molds 20,
When the movable mold 30 is opened after cooling the mold 30, the molded product is opened while being entrained in the movable mold 30. After that, the extrusion pin is moved forward to release the molded product from the movable mold 30. The molded product taken out from both the molds 20 and 30 is cut in the next step from the portion where the first overflow space 8 and the second overflow space 18 are connected to the second cavity 1b, and becomes the final molded product.

[0051]

[Embodiment 2] Next, the structure of the semi-molten metal forming die of Embodiment 2 will be described with reference to FIGS. First, FIG. 6 illustrates the first overflow gate portion 53 and the second overflow gate portion 53 for the purpose of removing the molten metal boundary Y generated at the joining portion J where the semi-molten metal M joins in the second cavity portion 50b according to the present embodiment. 63 is located on the same vertical axis, and is provided so that the vertical axis and the vertical axis of the mold intersect (mismatch).

In the second embodiment, a knuckle of an automobile part will be described as a target product in detail with reference to FIG. Here, the second cavity portion 50b and the third cavity portion 50c
Since and have the same structure, the second cavity portion 50b will be described as a representative. In FIG. 6, reference numeral 50 is a cavity portion, 50a is a first cavity portion, 50b is a second cavity portion, 53 is a first overflow gate portion, 54 is a first opening portion, 55 is a first overflow portion, and 58 is a first cavity portion. Overflow portion, 63 is a second overflow gate portion,
Reference numeral 65 is a second overflow portion, 66 is a second opening portion, and 68 is a second overflow space portion.

The second cavity portion 50b has an injection device 34.
And is connected to the upper part of the first cavity part 50a that is the most distant position from the side, and the third cavity part 50c is connected to the lower part of the first cavity part 50a. ing.

FIG. 7 is an enlarged front view of an essential part of FIG.
The cavity portion 50b is formed with an annular portion which serves as a bearing portion of the knuckle molded product, and the first cavity portion 5 is formed at the time of molding.
The tip of the semi-molten metal M filled in 0a flows toward the upper position while branching the annular portion of the second cavity portion 50b from the lower position in the left-right direction, and then joins at the upper diagonal position C and joins here. The semi-molten metal forming die 10 is capable of forming and integrating the portion J.

In the second embodiment, the first overflow space portion 58 and the first overflow space portion 58 are provided at the opposing upper and lower positions separated from the annular portion of the second cavity portion 50b with the joining portion J of the semi-molten metal M forming the molten metal boundary Y interposed therebetween. Two overflow spaces 68 are provided. The first overflow space portion 58 has a confluence portion J.
And the second overflow space 68 is located below the confluence J. The merging portion J has a center line position such that the second cavity portion 50b having the annular portion is symmetrical, and the second cavity portion 50b and the second overflow gate portion 6 are provided.
It is desirable to have a structure in which the center line passing through the center of 3 coincides with the center line.

First, the first overflow space 58 is
It comprises a first overflow gate section 53 and a first overflow section 55. Similarly, the second overflow space portion 68 is composed of the second overflow gate portion 63 and the second overflow portion 65.

The first overflow gate portion 53 and the second overflow gate portion 63 are connected between the annular portion of the second cavity portion 50b and the first overflow portion 55 or the second overflow portion 65, respectively. The first overflow gate portion 53 and the second cavity portion 5
The first opening 54 is opened at a portion orthogonal to the annular portion of 0b, and similarly, the second opening 66 is provided at a portion where the second overflow gate portion 63 is orthogonal to the annular portion of the second cavity portion 50b. It is open.

Thus, the first opening 54 and the second opening 6 are formed.
By providing 6 and 6, the hot water boundary Y generated at the junction J
More efficiently with the first overflow space 58 and the second overflow space 58.
It can be introduced into the overflow space 68 and removed. Further, the cross-sectional areas of the passages of the first overflow gate portion 53 and the second overflow gate portion 63 are configured to maintain the same cross-sectional area without changing midway. The first overflow gate unit 53 or the second overflow gate unit 53
Although the cross-sectional area of the overflow gate portion 63 is configured to have the same cross-sectional area through the communication passage, it may be changed.

When the cross-sectional area of the first overflow gate portion 53 or the second overflow gate portion 63 is large, when the annular portion of the second cavity portion 50b has a large size, the semi-molten metal M flows in the annular portion and then joins the junction portion J. At, the vectors in the opposite directions, which are close to the horizontal direction from the left and right, act and push each other. When such a horizontal vector acts, the first overflow gate unit 53 and the second overflow gate unit 53
The flow velocity flowing in the overflow gate portion 63 needs to be a cross-sectional area that allows a higher flow velocity than the flow velocity of the semi-molten metal M flowing in the annular portion.

On the other hand, when the size of the annular portion of the second cavity portion 50b is small, a vector moving slightly obliquely upward from the left and right acts on the confluence J after the semi-molten metal M flows in the annular portion. Will push in the opposite direction. When such a diagonally upward vector acts, the flow velocity of the semi-molten metal M flowing in the first overflow gate portion 53 and the second overflow gate portion 63 is determined by the dimension of the annular portion of the second cavity portion 50b. The cross-sectional area may be such that a slower flow velocity can be obtained as compared with the case where it is large.

In the second embodiment, the first overflow portion 55 and the second overflow portion 65 cannot be disposed at the mating surface position between the fixed die 20 and the movable die 30, and the inside of the movable die 30 separated from this mating surface position. Since the first overflow portion 55 and the second overflow portion 6 are
5 is regarded as an undercut, and the movable die 30 as shown in FIG.
A slide core pin 70 that can be freely taken in and out is arranged. In the present embodiment, the case where the first overflow portion 55 and the second overflow portion 65 are provided inside the movable die 30 due to the shape of the molded product has been described, but the present invention is not limited to this and the molded product Depending on the shape, the same result can be obtained by providing the fixed mold 20.

The slide core pin 70 is a slide core 72.
Is fixed to the front surface of the slide core 72, and can be moved forward and backward by a cylinder rod fixed to the rear end of the slide core 72. On the other hand, the second overflow portion 65 is arranged at a position facing the first overflow portion 55. The second overflow portion 65 has a structure that can be formed by putting a casting pin indicated by reference numeral 74 in and out of the mold. By the way, the first overflow section 5
5 and the volume V1 of the second overflow portion 65,
The volume may be substantially the same as the volume V2 of the annular portion of the second cavity portion 50b (V1 = V2) or may be different. Reference numeral 76 is a trap ring for trapping impurities such as oxides formed on the outer peripheral portion of the semi-molten metal M, and 77 is a biscuit.

A first opening 54 is opened in the orthogonal portion between the second cavity portion 50b and the first overflow gate portion 53, and similarly, in the orthogonal portion between the second cavity portion 50b and the second overflow gate portion 63, The second opening 66 is opened.

Reference numeral 78 indicates an air vent groove. In the second embodiment, since the first overflow portion 55 is arranged in the mold, when the semi-molten metal M is cast into the cavity portion 50 by the injection device 34 and is molded, the semi-molten metal M is crushed by the cavity portion 50. The air remaining in the cavity portion 50 flows into the first overflow portion 55 as the pressure is filled. The air flowing into the first overflow portion 55 is discharged to the outside of the molds 20 and 30 from an air vent groove 78 having a groove width larger than usual provided between the movable mold 30 and the slide core pin 70. It has become so. The air vent groove 78 has a groove width of 0.1 to 0.2 mm.

FIG. 8 is an explanatory view in which an air vent is provided between the extrusion pin and the mold, and FIG. 9 is a sectional view taken along the line AA of FIG. The extrusion pin 80 is shown in FIG. The push-out pin 80 is configured to come in and go out from the outside in a direction orthogonal to the movable die 30, and is arranged to press the molded article so that the molded article can be easily removed from the movable die 30. .

Between the push-out pin 80 and the movable die 30,
An air vent groove 82 is provided. The air vent groove 82 is formed in the first overflow portion 5 as shown in FIG.
The air flowing into the inside of the mold 5 is discharged to the outside of the molds 20 and 30 from an air vent groove 82 provided between the movable mold 30 and the extrusion pin 80 when the semi-molten metal M fills the cavity 50. It has become so. The gap between the push-out pin 80 and the movable die 30 is 0.1 mm, but this is a normal gap (0 mm) in order to easily discharge the air flowing into the first overflow portion 55 to the outside. .0
15 to 0.05 mm).

Since the cross-sectional areas of the first opening 54 and the second opening 66 have a rectangular shape and are substantially the same as the respective dimensional configurations shown in the first embodiment, the description thereof will be omitted here. .

Next, a semi-molten metal forming method using the semi-melt forming die 10 according to the second embodiment will be described.

First, similarly to the first embodiment, a molten aluminum alloy is poured from a ladle into a holding container (not shown) to obtain a semi-molten metal M. Then, when the molten metal reaches a target uniform temperature in the holding container, the completed semi-molten metal M is filled in the vertical sleeve 36 of the injection device 34.
When the vertical sleeve 36 of the injection device 34 is filled with the semi-molten metal M, both molds 20 and 30 are already closed, and the cavity 50 is provided between the fixed mold 20 and the fixed mold 30.
Are formed.

When the injection switch is turned on, the plunger rod 38 of the injection device 34 advances and the cavity 50 starts to be filled with the semi-molten metal M. As the plunger rod 38 advances, the semi-molten metal M is first filled in the third cavity portion 50c. When the semi-molten metal M flows into the third cavity portion 50c, the third cavity portion 5
The air staying at 0c is discharged from the air vent groove 82.

Subsequently, the semi-molten metal M at the leading end, which is rising while flowing in the first cavity portion 50a, reaches the inlet of the second cavity portion 50b. The semi-molten metal M that has reached the inlet of the second cavity portion 50b branches into two left and right parts according to the shape of the annular portion that serves as the bearing portion, and then gradually moves the annular portion in the clockwise direction and the counterclockwise direction. Proceed while filling, and join at the junction J. The air remaining in the second cavity portion 50b as the semi-molten metal M rises is discharged to the outside of the movable die 30 through an air vent groove 78 provided between the slide core pin 70 and the movable die 30.

The temperature of the semi-molten metal M flowing at the tip of the semi-molten metal M drops when flowing through the second cavity 50b, and even if the lowered tip parts of the semi-molten metal M merge with each other, they are not completely integrated. Therefore, in the merging portion J, a molten metal boundary Y is formed so as to extend in a direction orthogonal to the flow direction of the semi-molten metal M immediately before merging.

After the molten metal boundary Y is generated at the merging portion J, the semi-molten metal M starts to flow to the pulling first overflow gate portion 53 and the second overflow gate portion 63, respectively. It is entrained by the semi-molten metal M flowing inside the portion 53 and the second overflow gate portion 63.

The semi-molten metal M, which has begun to flow inside the first overflow gate portion 53 and the second overflow gate portion 63 while splitting, divides the first overflow overflow so as to cut and separate the molten metal boundary Y which causes a product defect. It flows into the part 55 and the second overflow part 65.

The semi-molten metal M is supplied to the first overflow portion 5
5 and the second overflow section 65 flow into the first cavity section 50a, until the volume occupied by the second overflow section 65 becomes full.
Filling into the second cavity portion 50b and the third cavity portion 50c is completed. After the filling is completed, both molds 20 and 30 are cooled, and when the movable mold 30 is opened, the molded product becomes the movable mold 3.
The mold is opened while being accompanied by 0. Thereafter, in order to make it easier to take out the molded product from the movable die 30, the first overflow portion 55 and the second overflow portion 65 which are undercut portions, the cast-out pin 74 and the slide core pin 70 at the forward limit are retracted and Then, the extrusion pin 80 is moved forward to release the molded product from the movable mold 30.

The molded product taken out from both molds 20 and 30 is cut in the next step from the portion where the first overflow space 58 and the second overflow space 68 are connected to the second cavity 50b, and the final molded product. Becomes

As is apparent from the above description,
According to the present invention, defects in the molded product due to the residual water and gas remaining during the molding of the semi-molten metal are prevented, so that a molded product with high mechanical strength can be stably manufactured.

[Brief description of drawings]

FIG. 1 is a schematic view of a mold for semi-molten metal forming in which a vertical axis of an overflow gate according to the present invention is arranged at a position matching a vertical axis of a mold, where (A) is a front view and (B) is a schematic view. Is a side view.

FIG. 2 is an explanatory diagram for explaining the behavior of the semi-molten metal viewed from the mold closing direction of the mold according to the present invention.

FIG. 3 is an explanatory diagram for explaining the behavior of the semi-molten metal viewed from a direction orthogonal to the mold closing direction of the mold according to the present invention.

4A and 4B are explanatory views illustrating a dimensional configuration of an overflow space portion according to the present invention, in which FIG. 4A is a front view and FIG. 4B is a side view.

FIG. 5 is a cross-sectional view of a main part of a mold provided with an overflow space portion according to the present invention, (A) a side view, and (B) a front view.

FIG. 6 is a schematic diagram of a semi-molten metal forming die in which the vertical axis of the overflow gate according to the present invention is arranged at a position that does not coincide with the vertical axis of the die.

FIG. 7 is an enlarged front view of a main part of FIG.

FIG. 8 is an explanatory diagram in which an air vent is provided between an extrusion pin and a mold.

9 is a cross-sectional view taken along the line AA of FIG.

FIG. 10 is a schematic view of a cavity structure having a structure of an overflow space provided in a conventional mold for forming a semi-molten metal.

FIG. 11 is a conceptual view of the behavior when the semi-molten metal M flows in the cavity viewed from the mold closing direction.

FIG. 12 is a conceptual diagram showing the behavior when the semi-molten metal M flows in the cavity when viewed from a direction orthogonal to the mold closing direction.

[Explanation of symbols]

1 cavity 1a First cavity part 1b Second cavity part 3 First overflow gate section 4 First opening 5 First overflow section 8 First overflow space 10 Mold for semi-molten metal forming 13 Second overflow gate section 15 Second overflow section 16 Second opening 18 Second overflow space 20 fixed type 30 movable 32 inlet 34 injection device 36 Vertical Sleeve 38 Plunger rod 50 cavity 50a First cavity part 50b Second cavity part 50c Third cavity part 53 First overflow gate section 54 First opening 55 First overflow section 58 First overflow space section 63 Second overflow gate section 65 Second overflow section 66 Second opening 68 Second overflow space section 70 Slide core pin 72 Slide core 74 Cast pin 76 trap ring 77 biscuits 78 Air vent groove 80 Extrusion Pin 82 Air vent groove 103 overflow gate 105 Overflow part 108 Overflow space part

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP 2002-321265 (JP, A) JP 2001-1125 (JP, A) JP 11-198171 (JP, A) JP 11-179772 ( JP, A) JP 9-272945 (JP, A) JP 5-260709 (JP, A) JP 1-286807 (JP, A) Actually opened 61-118709 (JP, U) Actually opened Sho 59-106661 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) B22D 17/22 B29C 45/26

Claims (6)

(57) [Claims] 1. A mold for forming a semi-molten metal in which a molten metal boundary is formed when a cavity portion having an annular portion is injected and filled, and a confluent portion in which the molten metal boundary is formed is sandwiched from the outside. A communication passage in the opposite position and a flow through the communication passage
Overflow to accept the semi-molten metal in the molten bath boundary
-The overflow space part consisting of
Of the cavity viewed from the direction orthogonal to the opening and closing direction of the mold
A semi-molten metal forming die, which is arranged over the entire width direction . Wherein a pair of said communication passage is claim 1 semi molten metal molding die, wherein the configured so as to form a same cross-sectional area. 3. The cavity portion is composed of a first cavity portion forming a main body portion and a second cavity portion provided in association therewith, and a tip portion of the semi-molten metal filled in the first cavity portion is and the melt merging portion which integrally joins after flowing from the left and right of the annular portion in the second cavity forming the annular portion, two disposed in positions facing each other across the solution hot junction section from the outside The first overflow portion and the second overflow portion are provided through the opening and the communication passage that communicates with each of the openings.
The semi-molten metal forming die according to 1 or 2 . 4. The cavity portion is composed of a first cavity portion forming a main body portion, a second cavity portion and a third cavity portion provided together with the first cavity portion, and a tip portion of the semi-molten metal forms an annular portion. The second cavity portion and the third cavity portion are arranged at positions facing each other with a molten metal confluence portion which flows from the left and right sides of the annular portion and then merges and is integrated. and two openings which are set, of any one of claims 1 or 2, characterized in first overflow portion through the communication passage which communicates with the providing the second overflow portions in each of the openings Item 5. A semi-molten metal forming die according to item. 5. The first overflow section or the second overflow section
At least one of the overflow parts is provided at a position recessed from the mating surface of the mold, and
The first overflow gate and the second overflow forming a path
Semi molten metal mold according to any of of the preceding claims 3 and 4 axis passing through the Rogeto portion is characterized by providing to intersect the longitudinal axis of the mold. It disposed the slide core into and out of 6. The mold, a slide core pin to prevent undercutting of said first overflow portion to the front end side of the slide core,
Semi molten metal mold according to claim 5, characterized in that disposed pins punching cast to prevent undercutting of said second overflow section.